Seagate Technology Incorporated

Maxtor Corporation

Richard Edward Martin

Erik Jon Hutchinson

Quinn Jay Haddock

Paul Julio Sonda

Michael L Mallary

Jason Wayne Riddering

Huazhou Lou

Abhay Tejmal Kataria

Brian D Strom

Scott Edward Ryun

Dipeshkumar J Purani

Stefan Andrei Ionescu

Robert Dean Turner

ChengYi Guo

Subhash Guddati

LingZhi Yang

Clifford Jayson Bringas Camalig

Mui Chong Chai

Steven B Marshall

Sandeep Dominic Sequeira

Christine Green

Stephen H Perlmutter

Gan Swee Chuan

Ximin Shan

Jesse Speckhard

Farhad Navid

Andy Chou

CheeWee Cheng

Jeff Nelson

Richard Arthur Herr

Alexander T Le

ShengYuan Lin

Salman Al Saif

SweeChuan Samuel Gan

KangHai Lim

Michael P DeFeo

Anton Viktorovich Goldade

Devon Dallmann

A method including obtaining a target actuation efficiency slope that is a linear function of temperature when a fixed active clearance is maintained between a transducing head and an adjacent storage surface in a sealed storage device. The target efficiency slope is obtained at least in part by a temperature dependence calibration of actuation efficiency. An operating temperature of the storage device is measure. Power to a clearance adjustment mechanism is adjusted to achieve the target actuation efficiency slope at the measured operating temperature.

Clearance control using actuation efficiency

Implementations described and claimed herein includes a storage device comprising a transducer head including at least one pair of read/write elements and a heat element to thermally protrude regions of the transducer head including the read/write elements. According to one implementation, the heat element includes at least one conductive portion of locally decreased resistance proximal to and between the pair of read/write elements to direct the thermally protruded close point away from a midpoint between the read/write elements.

Heater design with locally decreased resistance area for fly height control

Apparatus and method for managing a data storage device during extended idle conditions of the data storage device in which host access commands are not being received or serviced. In some embodiments, upon detection of an idle condition, a control circuit identifies a selected data transducer of the data storage device and a corresponding initial radial position of the data transducer with respect to an associated rotatable data recording surface. The control circuit performs a serpentine seek operation during the idle condition to gradually advance the selected data transducer in a selected radial direction across the data recording surface beginning at the initial radial position and ending at a final radial position. The serpentine seek operation prevents the transducer from being maintained in a stationary position during the idle condition, reducing the likelihood of damage through thermal asperity contact events, lubrication disturb, wear, etc.

Serpentine seeks during data storage device idle periods

Implementations described and claimed herein includes a storage device comprising a transducer heat including at least one pair of read/write elements and a heat shaped to thermally protrude regions of the transducer head including the read/write elements. According to one implementation, the heat element includes at least one conductive portion of locally decreased resistance proximal to and between the pair of read/write elements to direct the thermally protruded close point away from a midpoint between the read/write elements.

Heater design for fly height control

A lumped-parameter function &#x3b4; is determined that represents an average power dissipated by a write transducer when writing a signal to a magnetic recording medium. Temperatures of the write transducer are measured while varying the parameters to determine constants of the function &#x3b4;. The function &#x3b4; is used to adjust power applied to a clearance control heater when writing to the magnetic recording medium.

Lumped-parameter thermal model of a write transducer for clearance control on magnetic recording device

A reference track written to a magnetic recording medium includes at least two harmonics that facilitate measuring a clearance between a read/write head and the recording medium. A magnetic field is applied to the reference track that accelerates a thermal decay of the reference track without erasing data of the reference track.

Accelerating thermal decay of a harmonic-ratio reference track

A test track is written to a recording medium and includes a repeated series of reference patterns. The reference patterns each include a first portion with a high frequency pure tone and a second portion with a higher frequency component. A length of the first portion is greater than a length of the second portion. The series of reference patterns are read to determine first and second harmonic amplitudes, and a head-to-media clearance is determined based on the first and second amplitudes at first and second harmonic frequencies.

High frequency reference patterns used to determine head-to-media clearance

Method and apparatus for verifying and controlling a clearance distance of an object, such as but not limited to a fly height of a read/write transducer adjacent a recording medium in a data storage device. In accordance with some embodiments, a sensor is used to sense a plurality of patterns from an adjacent surface, with each pattern being written at a different constant frequency. A final clearance distance between the sensor and the surface is established in response to a multi-frequency response ratio from the sensor and a single frequency response ratio from the sensor.

Clearance distance verification and control

Apparatus and method for positional sensing and control. In accordance with some embodiments, a transducer is positioned adjacent a recording medium. The transducer includes a write element, a read element, a heater and a thermally responsive sensor. Power is applied to the heater to establish a selected fly height of the transducer relative to the medium. A contact event between the transducer and the medium is detected responsive to an accumulated plural count of pulses in a bias signal obtained from the thermally responsive sensor.

In situ sensor based contact detection

Testing and compensating for fly height of a head in a storage device during settling time using a head for use on a storage medium and a processor to idle the head for an idle time, unload the head from idle, and compensate for any unsettled fly height of the head using the idle time and at least a pre-determined clearance settling function over time from idle.

Head fly height testing and compensation

A transducer carrying structure includes a first portion carrying the transducer, a second portion spaced from the transducer, and a spacing control actuation system operable to adjust a position of the first portion of the transducer carrying structure. An overcoat is provided on a surface of the transducer carrying structure. The overcoat has a first thickness in the first region of the transducer carrying structure and a second thickness in the second region of the transducer carrying structure, the second thickness being greater than the first thickness. This configuration provides increased wear robustness to the transducer carrying structure without causing the transducer to be excessively spaced from a medium during operation of the transducer.

Dual thickness carbon overcoat

The present disclosure is directed to spectral analysis of a position error signal. In a particular embodiment, the method includes analyzing a spectral content of a position error signal. The method also includes comparing the spectral content to a threshold. Further, the method includes determining a result based on the comparing the spectral content to the threshold. In another particular embodiment, the spectral content of the position error signal is determined by performing a discrete fourier transform (DFT) on the error signal, determining a magnitude of the DFT output, and low pass filtering the magnitude.

Spectral analysis of a position error signal

In some embodiments of the present invention, a disk drive includes a rotatable data storage disk, a head, and a controller. The head is configured to fly on an air cushion relative to a data recording surface of the rotating disk while writing data to the data recording surface responsive to a write command from a host device or while reading data from the data recording surface to generate a read signal responsive to a read command from the host device. The controller is configured to measure flying height of the head relative to the data recording surface of the disk in response to sensing power-up of the disk drive and/or a shut-down command from the host device. The controller may measure the flying height in response to sensing power-up of the disk drive and, subsequent to measuring the flying height, may generate a ready signal to the host computer that indicates that the disk drive has powered-up and is ready to receive read/write commands from the host computer.

Methods and disk drive that measure head flying height at power-on/off

A disk drive () including one or more storage disks () and a head stack assembly () is provided herein. The head stack assembly () includes an actuator assembly () and a plurality of transducer assemblies (). The actuator assembly () moves the transducer assemblies () relative to the storage disks (). Each transducer assembly () includes a slider (), a load beam () and a head suspension () that secures the slider () the load beam (). Preferably, the slider () includes an air bearing surface () and one or more pads (). Importantly, the head suspension () maintains the slider () at a negative pitch static attitude. As a result thereof, the slider () is less likely to tip during shutdown and/or after vibration.

Device and method for improved stiction reliability in disk drives employing padded sliders

Methods and devices are provided that allow heads for use in disk drives to be tested in a helium environment in a cost-effective way with little or no impact on test time and with minimal consumption of helium.

Growing community of inventors

Longmont, CO, United States of America

Richard Edward Martin